Viruses are the simplest, smallest and often most rugged forms of life. The protective nanometer-scale proteinaceous shells (capsids) of viruses are particularly striking examples of biological materials evolution. These highly regular, self-assembled, nanometer sized containers are minimalistic in design, but combine complex passive and active functions. Besides chemical and physical protection, they are involved in the selective packing and injection of the viral genetic material. These objects illustrate an interesting array of basic physical principles which we wish to experimentally explore. Using atomic force microscopy, optical tweezers and fluorescence techniques we are studying the physical properties of viral capsids. Moreover, we investigate the mechanism of genome delivery and DNA packaging with single molecule methods.
Atomic force microscopy image of a Hepatitis B capsid (in T=4 protein configuration). A smaller T= 3 particle at lower magnification is show in the upper left corner. The corresponding height profiles (Lower Left Inset) distinguish between the T=3 and T=4 capsids, detecting the15% difference in diameter. The lateral apparent diameters are smeared by AFM tip convolution effects. Image from C. Uetrecht, C. Versluis, N. Watts, W.H. Roos, G.J.L. Wuite, P. Wingfield, A.C. Steven, A.J.R. Heck. Structure, Stability and Shape of Hepatitis B Virus Capsids.Proc. Natl. Acad. Sci. U. S. A. 105(27): 9216-9220 (2008)
Contact: Gijs Wuite, e-mail: GJL.Wuite@few.vu.nl